Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/test/serve/does_not_crash_if_an_unused_dart_file_has_a_syntax_error_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS d.file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library pub_tests;
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import 'utils.dart';
 
 main() {
   initConfig();
   withBarbackVersions("any", () {
     integration("doesn't crash if an unused .dart file has a syntax error", () {
-      d.dir(appPath, [
-        d.pubspec({
+      d.dir(appPath, [d.pubspec({
           "name": "myapp",
           "transformers": ["myapp/src/transformer"]
         }),
-        d.dir("lib", [d.dir("src", [
-          d.file("transformer.dart", REWRITE_TRANSFORMER),
-          d.file("unused.dart", "(*&^#@")
-        ])]),
-        d.dir("web", [
-          d.file("foo.txt", "foo")
-        ])
-      ]).create();
+            d.dir(
+                "lib",
+                [
+                    d.dir(
+                        "src",
+                        [
+                            d.file("transformer.dart", REWRITE_TRANSFORMER),
+                            d.file("unused.dart", "(*&^#@")])]),
+            d.dir("web", [d.file("foo.txt", "foo")])]).create();
 
       createLockFile('myapp', pkg: ['barback']);
 
       var server = pubServe();
       requestShouldSucceed("foo.out", "foo.out");
       endPubServe();
     });
   });
 }